Electric switch



Aug 13, 1942 T. w. THIRLWELL 2,293,318

ELECTRIC SWITCH Filed April 25, 1941 zoma's TV. Thi/"Zwaar INVENTORATTORN EYS Patented Aug. 18, 1942 UNITED STATES PTENT OFFICE 1 Claim.

' My invention relates to circuit' interrupters, and includes among itsobjects and advantages the provision of an improved general `purposeswitch of the silent action type.

In the accompanying drawing:

Figure 1 "is a face view of a switch in accordance with the invention; f

Figure 2 is a View taken from the position indicated by line 2--2 ofFigure 1 but showing the switch associated with the usual outlet boxemployed for wall installatiom Figure 3 is a sectional view takenalongthe line 3-3 of Figure 2;

Figure 4 is a sectional view taken along the line 4-4 of Figure 3;

Figure 5 isa face view of a modified form of the switch; and

Figure 6 is a sectional View taken along the line 6-6 of Figure 5.

In the embodiment selected to illustrate the invention, I make use of aninsulative switch housing I0 formed of molded composition, which housingis preferably of such size and contour as to operate in conjunction withthe usual outlet box II employed for wall installation and provided withthe usual wall plate I2. Tubular elements I3 and I4 are molded in theend walls of the housing I0, which housing has an opening IIE in oneside wall thereof. Both elements I3 and I4 are internally threaded, asat I6, for v connection with terminal screws I1 and IB.

A leaf contact I9 is xedly secured to the element I3, as by riveting 20,and this contact has an ear 2| positioned closel5r to the head of theterminal screw I1 to hold the looped end of the circuit wire closely tothe shank of the terminal screw `and underneath the head thereof. To theelement I4 is iiXedly secured one end of a flexible leaf contact 22, as.by riveting 23, and this contact is also provided with an ear 24 forthe same lpunpose as the ear 2|.

Fig. 3 illustrates the normal open circuit position of the contact 22,which provides spacing 25 between the contacts I9 and 22. Both contactsI9 `:and 22 are electrically related to their respective elements I3 andI4.

In the front wall 26 of the housing III is .provided an opening 21 lforthe accommodation of a switch lever 29. This lever is pivotally mountedintermediate its ends on a shaft 29 lying in slots 39 in the sidewalls3I Vof the housing. Plates 32 are secured to the walls 3I by rivets 33molded in the material of the housing. Each lplate is provided with twoears 34 positioned at right angles to their respective plates andoverlying the front face of the housing. rIvhe ears are cut away at 35in registration with the slots 30 for accommodation of the shaft 29, andthe ears of each plate have meeting tabs 33 which may be bent upwardlyto permit the shaft 29 to be pressed into position and then bentdownwardly over the shaft to hold it in place. Each end of the shaft isupset at 31 for coaction with theY plates 32 to restrain the shaft fromrelative endwise movement.

The inner end of Vthe switch lever 28 is fan shaped and lies closely tothe resilient contact 22. One edge of the inner end is rounded at 38,and the contact is bent to provide a cam run 39 lyingin the path of therounded surface 38. Fig. 4 illustrates the lev'er 28 in its two extremepositions. `In one position, the edge 40 of the lever engages the frontwall 26, as at 4I, while in the other extreme position, the leverengages the rWall 26, as at 42. The lever 28 in Fig. 4 is positioned inaccordance with its full line illustration of Fig. 4, fat which time therounded surface 38 is spaced from the cam run 39 so that the contact 22is in its normal circuit breaking yposition with respect to thestationary contact I9. Pivotal movement of the lever 2S to its dottedline position of Fig. 4 brings the rounded surface 38 into engagementwith the cam run 39 and fleXes the contact 22 rrnly against thestationary contact I9 for circuit closing purposes.

Adjacent one of the side walls 3l is positioned a bowed leaf spring 43which bears against one side of 'the switch lever 28 for pressing thelatter against the other side wall to the end that the switch lever maybe frictionally supported in its two positions. This spring is pressedinto slots 44 in the wall 26 and the tension of the spring is such as tohold the switch lever rmly in either position.

A switch in accordance with my invention is entirely silent in itsaction. The contact 22 flexes easily into engagement with the stationarycontact I9 and all the moving parts operate noiselessly.

Anchor plates 45 are secured to the housing YIII by rivets 45 molded inthe material of the housing. These plates are provided with openings 41for the reception of screws which may be threaded into the outlet box IIfor securing the housing to the box. Each plate 45 is also provided witha threaded opening 48 for the reception of screws 49 which hold the wallplate I2 in position.

Figs. 5 and 6 illustrate a diiierent form of the invention, wherein thetop wall 50 and the bottom wall are molded into a unitary structure withthe side walls 52, which are considerably shorter in length than the topand bottom walls. The housing of Figs. 5 and 6 conforms to the housingof Figs. l through 4 with respect to size and contour.

Tubular elements 53 are secured to the bottom wall 5| and are internallythreaded at 54 for the reception of terminal screws 55. One of thetubular elements 53 is provided with a contact 56 engageable by one endof a leaf contact 51 having its opposite end xedly secured to the otherelement 53. Contact 51 is of the resilient type and normally spaced fromthe fixed contact 56.

A slot 58 is provided in the front Wall 5| for the accommodation of alever 5.9 pivoted intermediate its ends on a shaft 60 secured to theside walls 52. A relatively flat face 6| is fashioned on the inner endof the switch lever 59 for engagement with the spring contact 51 whenthe latter is in the position of Fig. 6. Face 6| is so angled as toexert pressure on the spring eontact'51 for flexing the contact intoengagement with the xed contact 56 when the lever 59 is pivoted to thedotted line position of Fig. 6. The face BI is provided with a curvedcamming face 6,2 which acts on the spring contact 51 to flex Vit to thedotted line position of Fig. 6, and the curved camming face 62terminates in a flat face 63' whichY lies in engagement with the springcontact inthe dotted line position of the switch lever for holding thelatterrmly against the xed Contact 56.

In the full line position of the switch lever 59, as illustrated in Fig.6, the inner end hasengagement with the front wall 50, as at 64.V Atthe. same time, the switchv lever may have engagement with the edges ofthe front wall 5U so as to stop further pivotal movement of the switchlever when it reaches either of its two extreme positions. 'I'he switchof Figs. 5 and 6 also operates silently.

Anchor plates 66 are secured to the housing by rivets 61, and theseplates are also provided with threaded openings 68 corresponding to theopenings 48.

Without further elaboration, the foregoing will so fully illustrate myinvention that others may, by applying current knowledge, readily adaptthe same for use under various conditions of service.

I claim:

A switch comprising an nsulative body having a face wall provided withan opening and an interior cavity, a fixed contact secured to theinsulative body inside said cavity, a flexible contact secured to saidbody inside said cavity and normally spaced from said xed contact, aswitch lever pivoted to said body and having camming engagement withsaid ilexible contact when pivoted in one direction for bending theflexible Contact into circuit closingA engagement with said xed contactbut relieving pressure on the flexible Contact when pivoted intheopposite direction, said flexible contact comprising a flatstrap-like member lying atwise adjacent one side of the switch lever andhaving a cam formation lying in the path of the switch lever, and a atspring bearing flatwise against Vone side ofi-saidV switch lever forurging the latter against one wall face dening said opening forfrictionallyv supporting the switch lever against accidental pivotalmovement.

THOMAS W. THIRLWELL.

